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Background: Acute Intermittent Porphyria (AIP) is a rare inherited autosomal dominant disorder of heme biosynthesis. Porphyria-associated kidney disease occurs in more than 50% of the patients with AIP, and end stage renal disease (ESRD) can be a devastating complication for AIP patients. The outcomes of AIP patients after kidney transplantation are poorly known., Methods: We examined the outcomes of 11 individuals with AIP, identified as kidney transplant recipients in the French Porphyria Center Registry., Results: AIP had been diagnosed on average 19 years before the diagnosis of ESRD except for one patient in whom the diagnosis of AIP had been made 5 years after the initiation of dialysis. Median follow-up after transplantation was 9 years. A patient died 2 months after transplantation from a cardiac arrest and a patient who received a donation after cardiac death experienced a primary non-function. No rejection episode and no noticeable adverse event occurred after transplantation. Serum creatinine was on average 117 μmol/l, and proteinuria <0.5 g/l in all patients at last follow up. All usually prescribed drugs after transplantation are authorized except for trimethoprim/sulfamethoxazole. Critically, acute porphyria attacks almost disappeared after kidney transplantation, and skin lesions resolved in all patients., Conclusion: Kidney transplantation is the treatment of choice for AIP patients with ESRD and dramatically reduces the disease activity., Competing Interests: Declaration of Competing Interest This research was unfunded and the authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier Inc. All rights reserved.)

While direct measurements of glomerular filtration rate (GFR) provide the most accurate evaluation of pre-donation kidney function, guidelines do not systematically require the use of a reference method. We evaluated whether and to what extent relying upon creatinine-based estimating equations (eGFR) rather than direct measurement of GFR (mGFR) alters the selection of potential living donors. We compared the impact of 4 equations (the MDRD study equation, the CKD-EPI equation, the revised Lund-Malmö equation, and the full age spectrum [FAS] equation) on the evaluation of 2733 potential donors with GFR measured by reference methods. We also considered the impact of using either absolute or age-adapted GFR thresholds. The CKD-EPI and FAS equations had the best performances (P10 of 50.6% and 47.8%; P30 of 94.4% and 93.1%, respectively) and led to the lowest proportion of improperly evaluated candidates. Misclassification was more frequent when GFR adequacy was defined as an absolute threshold of 90 ml/min/1.73m 2 as compared to an age-adapted definition (26% and 5%, respectively). Interpretation of eGFR according to an absolute threshold of 90 ml/min/1.73m 2 identified 1804 candidates eligible to donate, compared to 2648 when mGFR was interpreted with age-adapted thresholds. We conclude that creatinine-based estimates cannot substitute for direct GFR measurement to evaluate candidates for kidney donation. When reference methods for direct GFR measurement are not available, our data suggest that a strategy based on age-adapted eGFR values estimated with either the CKD-EPI or FAS equation should be preferred., (Copyright © 2019 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Treatment of acute antibody-mediated rejection (AMR) is based on a combination of plasma exchange (PE), IVIg, corticosteroids (CS), and rituximab, but the place of rituximab is not clearly specified in the absence of randomized trials., Methods: In this phase III, multicenter, double-blind, placebo-controlled trial, we randomly assigned patients with biopsy-proven AMR to receive rituximab (375 mg/m) or placebo at day 5. All patients received PE, IVIg, and CS. The primary endpoint was a composite of graft loss or no improvement in renal function at day 12., Results: Among the 38 patients included, at 1 year, no deaths occurred, but 1 graft loss occurred in each group. The primary endpoint frequency was 52.6% (10/19) and 57.9% (11/19) in the rituximab and placebo groups, respectively (P = 0.744). Renal function improved in both groups, as soon as day 12 with no difference in serum creatinine level and proteinuria at 1, 3, 6, and 12 months. Supplementary administration of rituximab and total number of IVIg and PE treatments did not differ between the 2 groups. Both groups showed improved histological features of AMR and Banff scores at 1 and 6 months, with no significant difference between groups but with a trend in favor of the rituximab group. Both groups showed decreased mean fluorescence intensity of donor-specific antibodies as soon as day 12, with no significant difference between them but with a trend in favor of the rituximab group at 12 months., Conclusions: After 1 year of follow-up, we observed no additional effect of rituximab in patients receiving PE, IVIg, and CS for AMR. Nevertheless, our study was underpowered and important differences between groups may have been missed. Complementary trials with long-term follow-up are needed.

Markers of epithelial-mesenchymal transition (EMT) may identify patients at high risk of graft fibrogenesis who could benefit from early calcineurin inhibitor (CNI) withdrawal. In a randomized, open-label, 12-month trial, de novo kidney transplant patients received cyclosporine, enteric-coated mycophenolate sodium (EC-MPS) and steroids to month 3. Patients were stratified as EMT+ or EMT- based on month 3 biopsy, then randomized to start everolimus with half-dose EC-MPS (720 mg/day) and cyclosporine withdrawal (CNI-free) or continue cyclosporine with standard EC-MPS (CNI). The primary endpoint was progression of graft fibrosis (interstitial fibrosis/tubular atrophy [IF/TA] grade increase ≥1 between months 3-12) in EMT+ patients. 194 patients were randomized (96 CNI-free, 98 CNI); 153 (69 CNI-free, 84 CNI) were included in histological analyses. Fibrosis progression occurred in 46.2% (12/26) CNI-free EMT+ patients versus 51.6% (16/31) CNI EMT+ patients (p = 0.68). Biopsy-proven acute rejection (BPAR, including subclinical events) occurred in 25.0% and 5.1% of CNI-free and CNI patients, respectively (p < 0.001). In conclusion, early CNI withdrawal with everolimus initiation does not prevent interstitial fibrosis. Using this CNI-free protocol, in which everolimus exposure was relatively low and administered with half-dose EC-MPS, CNI-free patients were overwhelmingly under-immunosuppressed and experienced an increased risk of BPAR., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Chronic lymphocytic leukemia and small lymphocytic lymphoma are 2 different presentations of the most common B-cell neoplasm in western countries (CLL/SLL). In this disease, kidney involvement is usually silent, and is rarely reported in the literature. This study provides a clinicopathological analysis of all-cause kidney disease in CLL/SLL patients., Methods: Fifteen CLL/SLL patients with kidney biopsy were identified retrospectively. Demographic, clinical, pathological and laboratory data were assessed at biopsy, and during follow-up., Results: At biopsy 11 patients presented impaired renal function, 7 patients nephrotic syndrome, 6 patients dysproteinemia, and 3 patients cryoglobulinemia. Kidney pathology revealed CLL/SLL-specific monoclonal infiltrate in 10 biopsies, glomerulopathy in 9 biopsies (5 membranoproliferative glomerulonephritis, 2 minimal change disease, 1 glomerulonephritis with organized microtubular monoclonal immunoglobulin deposits, 1 AHL amyloidosis). Five patients presented interstitial granulomas attributed to CLL/SLL. After treatment of the hematological disease, improvement of renal function was observed in 7/11 patients, and remission of nephrotic syndrome in 5/7 patients. During follow-up, aggravation of the kidney disease systematically occurred in the absence of favorable response to hematological treatment., Conclusions: A broad spectrum of kidney diseases is associated with CLL/SLL. In this setting, kidney biopsy can provide important information for diagnosis and therapeutic guidance.

Background: Although several risk factors associated with complications after renal biopsy (RB) have been identified, recommendations for RB procedures are still lacking. Our working group, appointed by the scientific commission of the Société de néphrologie in France, aimed to depict the main aspects of the practice of RB in adults in France, before establishing some guidelines., Methods: Members of the Société de néphrologie in France were asked to participate to a questionnaire survey on RB procedures., Results: Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals, and 12 in private centers) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to less than ten per year. Transjugular RB was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of hemorrhagic risk factors, care of patients with antiplatelet agents and hemorrhagic risk factors, and radiological guidance. Early discharge (<12 hours) was the rule in three (4.1%) units for native kidney biopsies and in ten (28.6%) units for graft biopsies., Conclusions: Our study is the first to provide a representative picture of "everyday" RB practices in a country. Consensual recommendations on all points mentioned are provided here., (Copyright © 2012. Published by Elsevier SAS.)

Studies of the primary cilium, now known to be present in all cells, have undergone a revolution, in part, because mutation of many of its proteins causes a large number of diseases, including cystic kidney disease. Bardet-Biedl syndrome (BBS) is an inherited ciliopathy characterized, among other dysfunctions, by renal defects for which the precise role of the cilia in kidney function remains unclear. We studied a cohort of patients with BBS where we found that these patients had a urinary concentration defect even when kidney function was near normal and in the absence of major cyst formation. Subsequent in vitro analysis showed that renal cells in which a BBS gene was knocked down were unciliated, but did not exhibit cell cycle defects. As the vasopressin receptor 2 is located in the primary cilium, we studied BBS-derived unciliated renal epithelial cells and found that they were unable to respond to luminal arginine vasopressin treatment and activate their luminal aquaporin 2. The ability to reabsorb water was restored by treating these unciliated renal epithelial cells with forskolin, a receptor-independent adenylate cyclase activator, showing that the intracellular machinery for water absorption was present but not activated. These findings suggest that the luminal receptor located on the primary cilium may be important for efficient transepithelial water absorption.

Background: Although several risk factors associated with complications after renal biopsy (RB) have been identified, the gold standard for RB procedures remains to be defined. Practices vary widely among nephrologists, depending on personal experience and the availability of particular techniques. The purpose of our study was to depict the main aspects of the practice of RB in adults in France., Methods: Members of the Société de Néphrologie in France were asked to participate in a questionnaire survey on RB procedures., Results: Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals and 12 in private centres) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to <10 per year. Transjugular renal biopsy was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of haemorrhagic risk factors, management of patients with antiplatelet agents and haemorrhagic risk factors, and radiological guidance. Early discharge (<12 h) was the rule in 3 (4.1%) units for native kidney biopsies and in 10 (28.6%) units for graft biopsies., Conclusions: Our study is the first to provide a representative picture of 'everyday' RB practices in a country. Important variations in procedures were observed. Our study may represent a preliminary step for the elaboration of guidelines for all aspects of RB practices.

During normal pregnancy, renal blood flow and GFR increase gradually until they reach a peak of about 150% of their normal values by the end of the 1(st) trimester. This increase in GFR is secondary to the extra-cellular compartment expansion caused by a positive sodium balance of about 500-900 mmol which is in turn associated with a water retention amounting 6 to 8 liters. Blood pressure decreases during a normal pregnancy because of the decrease in peripheral vascular resistance. This drop in blood pressure is limited by the renin-angiotensin system. Blood pressure gradually recovers during the 3(rd) trimester. Systemic hypertension, proteinuria >0.3 g/day and edema are the usual signs leading to the diagnosis of PE. However, any of the above listed signs found in isolation can be a tell tale sign of PE and must therefore prompt for the identification of a possible fetal effect The differential diagnosis of PE includes essential hypertension and hypertension secondary to a pre-existing renal failure. In the latter, signs of renal impairment early in the pregnancy, or (and) renal failure prior to the pregnancy are of important diagnostic clues. Causes of acute renal failure during pregnancy are numerous. PE associated acute renal failure presents in 5-10% of severe forms of PE. This is always a bad prognostic sign with a predicted mortality of 10%. Histological features are those of acute tubular necrosis with "endotheliosis" an inflammation of the glomerular endothelium. This renal impairment is frequently complicated by pulmonary edema. Passed the acute phase, the recovery of the renal function is usually complete. An acute renal failure during pregnancy can also be secondary to a pre-existing renal impairment suddenly aggravated by PE. In this setting, the probability of these patients requiring long term dialysis is high. Post-partum Haemolytic-Uremic Syndrome (HUS), although rare, is a serious condition which, following delivery, will require an early diagnosis (haemolysis, hypertension, acute renal failure) and urgently require symptomatic, perhaps specific, treatment (Plasma exchange transfusion)., (Copyright 2010 Elsevier Masson SAS. All rights reserved.)

Nephrotoxicity is an inherent adverse effect of certain anticancer drugs. Anti neoplasic drugs have a narrow therapeutic index and the amount of drug necessary to produce a significant reduction in tumour burden usually produces significant nephrotoxicity. The dosage used in clinical trials represents often the maximum tolerated doses determined during phase I drug evaluation. Greater toxicity is acceptable during curative therapy than during palliative therapy. But cancer patients often exhibit excretory reduced organ function. Modulation of pharmacokinetics and pharmacodynamics of these drugs in cancer patients is therefore necessary in order to improve tolerance. Patients with malignancies are particularly vulnerable to development of renal abnormalities. Conversely, patients with renal abnormalities who have undergone kidney transplantation are at high risk for malignancy. Clinical syndromes of renal involvement are diverse and sometimes insidious. Despite the recent advances in understanding the mechanism of anticancer drug nephrotoxicity, prevention still relies on drug dosage decrease and active screening for renal abnormalities as part of the usual biological work up in patients treated with anticancer drugs.

Renal morphological and functional changes occur in the elderly. Between the ages of 50 and 80 years the renal mass diminishes by a mean of 20 percent, to the expense of the renal cortex. Glomerular sclerosis results in a gradual fall in the number of functioning glomeruli. Simultaneously, a decrease of about 7 percent in glomerular filtration rate per decade after the age of 40 years and a 10 percent decrease in renal plasma flow per decade, and therefore an increase in filtration fraction, are observed. These haemodynamic abnormalities are accompanied by changes in tubular function, including a delay in renal adjustment to sodium overload, and above all to sodium restriction, together with a decrease in concentrating and, to a lesser extent, diluting capacity. In actual fact, the intensity of glomerular sclerosis varies considerably from one subject to another, and the decrease in glomerular filtration rate is far from being constant. These changes are perhaps not ineluctably associated with aging; they might result from pathological processes that have gone unnoticed.

The antitumor drug celiptium (N2-methyl-9-hydroxyellipticinium) is an ellipticine derivative effective in experimental tumors and in man. The major side effect is nephrotoxicity. The impairment of renal function is studied in rats following a single i.v. dose of 20 mg/kg celiptium and a long-term study (day 2 to day 60). A loss of body weight is noted in celiptium-treated animals between day 4 and day 15, and recovery occurs between day 15 and day 60. Histologic study shows cortical lesions characterized by focal necrosis of proximal tubules without any glomerular, interstitial, and vascular alterations on day 8. It is to be noted that any medullary lesions were not shown. A polyuria and a decreased creatinine clearance are reported on day 8. We were interested in a special study of this polyuria. For this study, rats were water deprived between day 6 and day 8 following celiptium administration. The decrease of urinary osmolality is not recovered after dehydration and exogenous vasopressin derivative (dD AVP) does not correct the renal concentration defect. AVP plasma levels increase after dehydration. These results suggest a pitressino-resistant urinary concentrating inability in celiptium-treated rats.

A high protein meal acutely stimulates the glomerular filtration rate. In order to assess the possible role of atrial natriuretic peptide (ANP) as a mediator of this renal response, the ANP plasma concentrations were measured with a sensitive radioimmunoassay method before and after a large protein load (1.5 g/kg body weight given as a meat meal). Creatinine clearance increased significantly while fractional excretion of sodium remained constant. ANP plasma concentrations did not change after the protein load and the intra-individual variations of creatinine clearance were not correlated with the intra-individual changes in ANP plasma concentrations. It was concluded that ANP was probably not involved in the renal haemodynamic changes observed after a large protein load.

Apalcilline is a new semi-synthetic penicillin. More than 4,000 patients were treated with this antibiotic but an increase level of serum creatinine was noted in 18 cases. Responsibility of apalcilline in this side effect could be possible in 5 cases, doubtful in 13 cases. We decided to study renal function of normal volunteers treated with 4 gr apalcilline. Three periods were realised: a control period (80 min), a treatment period (60 min), a post-treatment period (40 min). Inulin and PAH infusion lasted during all these three periods. After the control period 2 gr apalcilline was injected as a bolus followed by a 2 gr apalcilline perfusion for one hour. Urinary volume was measured every 20 min. Creatinine, inulin, PAH clearances, sodium, potassium, calcium, magnesium urinary excretion were calculated for each period. Urinary B2-microglobulin excretion was also appreciated. Analysis of variance was done. We did not observe any variation of creatinine, inulin clearances or variation of urinary electrolytes output PAH clearance was significantly decreased during alpacilline infusion. Apalcilline seems competitive with PAH for proximal tubular secretion. Nevertheless apalcilline did not induce any more renal dysfunction.

Kidney is the main source of the production of renin and angiotensin, while also being one of their main target organs. This study was designed to determine the regional distribution of angiotensin-I-converting enzyme (ACE) in the kidney using a biochemical approach. Interspecies variations were analyzed in human, monkey, rabbit, dog and rat kidneys. Kidney ACE content differed among species with decreasing contents as follows: rabbit greater than human greater than monkey greater than dog greater than rat. In rabbit, human, monkey and dog kidneys, we observed predominant cortical distribution of ACE compared with the medulla or papilla; median cortex/papilla ACE activity ratio was 19, 14, 9 and 7 for the rabbit, human, dog and monkey, respectively. In rat kidney, ACE predominantly distributes in the outer medulla, while cortex ACE content appears to be low. The difference in ACE distribution in the rat kidney and to a lesser extent in the dog kidney when compared to rabbit, monkey or man should be taken into account when extrapolating to the human renal hemodynamic studies, which are frequently performed in rats or dogs.

To assess the role of gallium-67 (67Ga) scintigraphy in the diagnosis of glomerular diseases, we performed the following technique in 39 patients with glomerulonephritis (GN) who underwent simultaneous Ga scan and histologic examination. 72 hours after IV injection of Ga citrate (2 mCi), isotopic kidney activity (normally undetectable) was compared to the activity of the liver and quantified as follows: less than (1+), equal to (2+) or greater than (3+) that of the liver. Renal biopsy was performed at the same time to evaluate the type of the GN and to quantify interstitial cellular infiltration. Proteinuria, serum albumin and creatinine were measured. There was a significant correlation between the level of 67Ga kidney activity and the degree of proteinuria and hypoalbuminemia. On the contrary, no correlation was found between isotopic activity and the degree of renal failure or the degree of interstitial cellular infiltration. Increased kidney 67Ga activity did not appear characteristic of a specific histologic type of GN. Increased glomerular permeability may alter renal uptake of Ga; therefore 67Ga scanning does not appear to contribute significantly to the diagnosis and the follow-up of either primary or secondary GN.

The tissue distribution of Perindopril, a new potent inhibitor of the angiotensin-converting enzyme (ACE), was studied after in vivo intravenous injection into rabbits of tracer amounts of the tritiated drug either alone (no modification of the renin angiotensin system) or along with a pharmacologic dose of 10 mg/kg unlabelled Perindopril. Lung and kidneys were the most densely labelled tissues. Kidney distribution of tritiated Perindopril was studied either by histo-autoradiography or by measurement of radioactivity in the homogenates of dissected kidney zones. A close parallelism was found between the distribution patterns of ACE and radioactivity throughout the kidney. Tritiated-Perindopril binding was inhibited by concurrent treatment of the animals with the unlabelled drug or pretreatment with Captopril. Autoradiographic study of kidney slices after the administration of tracer amounts of Perindopril showed an intense labelling of the glomerular mesangium and of endothelial structures of blood vessels, and a lack of labelling of tubular epithelial cells. The possible occurrence of two pools of "ACE-like" activity in the kidney is discussed, namely i) one pool which is labelled by tritiated Perindopril, located in glomerular mesangium and endothelial structures which may be involved in the pharmacological action of ACE inhibitors; and ii) a second pool located in the proximal-tubule cell brush-border, remaining unlabelled by Perindopril, for which the high amount of neutral endopeptidase present at this site may be responsible.

Background and purpose: Neurological manifestations in coronavirus disease (COVID)‐2019 may adversely affect clinical outcomes. Severe COVID‐19 and uremia are risk factors for neurological complications. However, the lack of insight into their pathogenesis, particularly with respect to the role of the cytokine release syndrome (CRS), is currently hampering effective therapeutic interventions. The aims of this study were to describe the neurological manifestations of patients with COVID‐19 and to gain pathophysiological insights with respect to CRS. Methods: In this longitudinal study, we performed extensive clinical, laboratory and imaging phenotyping in five patients admitted to our renal unit. Results: Neurological presentation included confusion, tremor, cerebellar ataxia, behavioral alterations, aphasia, pyramidal syndrome, coma, cranial nerve palsy, dysautonomia, and central hypothyroidism. Notably, neurological disturbances were accompanied by laboratory evidence of CRS. Severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) was undetectable in the cerebrospinal fluid (CSF). Hyperalbuminorrachia and increased levels of the astroglial protein S100B were suggestive of blood−brain barrier (BBB) dysfunction. Brain magnetic resonance imaging findings comprised evidence of acute leukoencephalitis (n = 3, one of whom had a hemorrhagic form), cytotoxic edema mimicking ischaemic stroke (n = 1), or normal results (n = 2). Treatment with corticosteroids and/or intravenous immunoglobulins was attempted, resulting in rapid recovery from neurological disturbances in two cases. SARS‐CoV2 was undetectable in 88 of the 90 patients with COVID‐19 who underwent Reverse Transcription‐PCR testing of CSF. Conclusions: Patients with COVID‐19 can develop neurological manifestations that share clinical, laboratory and imaging similarities with those of chimeric antigen receptor T‐cell‐related encephalopathy. The pathophysiological underpinnings appear to involve CRS, endothelial activation, BBB dysfunction, and immune‐mediated mechanisms. [ABSTRACT FROM AUTHOR]